Air intake system for internal combustion engine

ABSTRACT

An intake manifold is provided that controls swirl on entry to a combustion chamber. Each intake manifold includes a fin or rib portion positioned to reduce or eliminate swirl induced by the configuration of the intake manifold, particularly when used in a large engine having a left bank and a right bank of combustion chambers. By controlling swirl induced by the intake manifold, swirl consistency is improved between engine cylinders and between the left bank and the right bank, improving the consistency of power output and reducing emissions, particularly particulate emissions, also called smoke.

PRIORITY

The present application is a divisional of U.S. patent application Ser.No. 13/782,997 titled AIR INTAKE SYSTEM FOR INTERNAL COMBUSTION ENGINE,filed Mar. 1, 2013, the priority of which is hereby claimed and thedisclosure of which is hereby incorporated by reference.

TECHNICAL FIELD

This disclosure relates to an air intake system for internal combustionengines, and more particularly to an air intake system, including fin orrib portions positioned at an interface between the air intake systemand a combustion chamber of the internal combustion engine, where thefin or rib portions may be integrated into the air intake system.

BACKGROUND

Internal combustion engines require intake air be introduced in acombustion chamber as part of a combustion process. The intake air istypically introduced in the combustion chamber in a way that causes theintake air to swirl in the combustion chamber, which helps to mix theair and fuel introduced to the combustion chamber. Uniform andconsistent mixing of intake air provides consistent power output fromeach combustion chamber and can provide decreased emissions, especiallydecreased particulate emissions, also described as smoke.

SUMMARY

This disclosure provides an internal combustion engine comprising anengine body, a first intake manifold and a second intake manifold. Theengine body includes a plurality of left bank combustion chambers and aplurality of right bank combustion chambers. The first intake manifoldis positioned on the left bank side and the second intake manifold ispositioned on the right bank side. Each of the first and second intakemanifolds is attached to the engine body. Each of the first and secondintake manifolds includes a longitudinally extending airflow passage, abody interior surface forming the longitudinally extending airflowpassage, a plurality of inlet openings formed in the body interiorsurface, a plurality of outlet openings, and a plurality of transverseairflow passages. Each of the plurality of transverse airflow passagesextends between at least one of the plurality of inlet openings and atleast one of the plurality of outlet openings and includes alongitudinal transverse passage axis and a passage interior surface.Each of the first and second intake manifolds further includes at leastone fin portion extending radially inward from the passage interiorsurface into each of the plurality of transverse airflow passages andextending in a direction along the longitudinal transverse passage axis.The longitudinal transverse passage axis is curved to form a transversepassage angle and the transverse airflow passage is positioned tointersect the longitudinally extending airflow passage at a transversepassage connection angle.

This disclosure also provides an internal combustion engine comprisingan engine body, a first intake manifold, a second intake manifold, and aspacer portion. The engine body includes a plurality of left bankcombustion chambers and a plurality of right bank combustion chambers.The first intake manifold is positioned on the left bank side and thesecond intake manifold positioned on the right bank side. Each of thefirst and second intake manifolds is attached to the engine body. Eachof the first and second intake manifolds includes a longitudinallyextending airflow passage, a body interior surface forming thelongitudinally extending airflow passage, a plurality of inlet openingsformed in the body interior surface, a plurality of outlet openings, anda plurality of transverse airflow passages. Each of the plurality oftransverse airflow passages extends between one of the plurality ofinlet openings and one of the plurality of outlet openings and includesa longitudinal transverse passage axis. The longitudinal transversepassage axis is curved to form a transverse passage angle, and thetransverse airflow passage is positioned to intersect the longitudinallyextending airflow passage at a transverse passage connection angle. Aspacer portion is positioned between the first intake manifold and theengine body and a spacer portion is positioned between the second intakemanifold and the engine body. Each spacer portion includes a pluralityof spacer passages and at least one fin portion. The plurality of spacerpassage is positioned to connect the plurality of transverse airflowpassages to the engine body. The at least one fin portion extends fromthe spacer portion into each transverse airflow passage in a directionalong the longitudinal transverse passage axis.

This disclosure also provides an internal combustion engine comprisingan engine body, a first intake manifold, a second intake manifold, and afin insert portion. The engine body includes a plurality of left bankcombustion chambers and a plurality of right bank combustion chambers.The first intake manifold is positioned on the left bank side and thesecond intake manifold is positioned on the right bank side. Each of thefirst and second intake manifolds is attached to the engine body. Eachof the first and second intake manifolds includes a longitudinallyextending airflow passage, a body interior surface forming thelongitudinally extending airflow passage, a plurality of inlet openingsformed in the body interior surface, a plurality of outlet openings, anda plurality of passage interior surfaces, each passage interior surfaceforming a transverse airflow passage. Each of the plurality oftransverse airflow passages extends between at least one of theplurality of inlet openings and at least one of the plurality of outletopenings. Each of the plurality of transverse airflow passage includes alongitudinal transverse passage axis and includes at least one grooveformed in each passage interior surface and extending in a directionalong the longitudinal transverse passage axis. The longitudinaltransverse passage axis is curved to form a transverse passage angle.The transverse airflow passage is positioned to intersect thelongitudinally extending airflow passage at a transverse passageconnection angle. The fin insert portion is positioned in the at leastone groove. The fin insert portion extends radially inward from thepassage interior surface into the transverse airflow passage.

This disclosure also provides an internal combustion engine comprisingan engine body, a first intake manifold, a second intake manifold, atleast one groove, and a fin insert. The engine body includes a pluralityof left bank combustion chambers, a plurality of right bank combustionchambers, and a plurality of cylinder heads positioned to cover the leftbank combustion chambers and the right bank combustion chambers. Each ofthe plurality of cylinder heads includes a plurality of head inletopenings and a plurality of head interior surfaces, each head interiorsurface forming a head passage, each head passage including alongitudinal head passage axis and connecting at least one head inletopening to at least one combustion chamber. The first intake manifold ispositioned on the left bank side and the second intake manifold ispositioned on the right bank side. Each of the first and second intakemanifolds is attached to the engine body and includes a longitudinallyextending airflow passage, a body interior surface forming thelongitudinally extending airflow passage, a plurality of inlet openingsformed in the body interior surface, a plurality of outlet openings, anda plurality of passage interior surfaces. Each passage interior surfaceforms a transverse airflow passage. Each transverse airflow passageextends between at least one of the plurality of inlet openings and atleast one of the plurality of outlet openings and includes alongitudinal transverse passage axis. The longitudinal transversepassage axis curves to form a transverse passage angle. The transverseairflow passage is positioned to intersect the longitudinally extendingairflow passage at a transverse passage connection angle. Each outletopening is positioned to connect at least one longitudinally extendingairflow passage with at least one head passage. The at least one grooveis formed in at least one of each group including the passage interiorsurface and the head interior surface extending between each inletopening and each combustion chamber. The at least one groove extends ina direction along at least one of the longitudinal transverse passageaxis and the longitudinal head passage axis. The fin insert portion ispositioned in the at least one groove, the fin insert portion extendsradially inward from at least one of the passage interior surface andthe head interior surface into the respective transverse airflow passageor head passage.

Advantages and features of the embodiments of this disclosure willbecome more apparent from the following detailed description ofexemplary embodiments when viewed in conjunction with the accompanyingdrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a portion of a first conventional internalcombustion engine.

FIG. 2 is an end elevation view of the internal combustion engine ofFIG. 1 along the lines 2-2.

FIG. 3 is a plan view of a cylinder head and an intake manifold portionfrom a left bank side of the internal combustion engine of FIG. 1, and acylinder head and an intake manifold from a right bank side of theinternal combustion engine of FIG. 1.

FIG. 4 is a perspective view of one left bank intake manifold portionand one right bank intake manifold portion of FIG. 3 showing a stylizedairflow from each intake manifold portion.

FIG. 5 is a perspective view of an intake manifold portion in accordancewith a first embodiment of the present disclosure.

FIG. 6 is a perspective sectional view of the intake manifold portion ofFIG. 5 along the lines 6-6 in FIG. 5.

FIG. 7 is a perspective view of an intake manifold portion in accordancewith a second embodiment of the present disclosure.

FIG. 8 is a perspective view of a part of a cylinder head in accordancewith a third embodiment of the present disclosure.

FIG. 9 is a sectional view of the cylinder head of FIG. 8 along thelines 9-9.

FIG. 10 is an elevation view of a part of the cylinder head of FIG. 8.

FIG. 11 is a perspective view of a fin insert portion compatible withthe cylinder head of FIG. 8 in accordance with a fourth embodiment ofthe present disclosure.

FIG. 12 is a perspective view of a transverse airflow passage inaccordance with a fifth exemplary embodiment of the present disclosure.

FIG. 13 is a perspective view of a transverse airflow passage inaccordance with a sixth exemplary embodiment of the present disclosure.

FIG. 14 is a perspective view of a transverse airflow passage inaccordance with a seventh exemplary embodiment of the presentdisclosure.

FIG. 15 is an end view of a transverse airflow passage in accordancewith an eighth exemplary embodiment of the present disclosure.

FIG. 16 is an end view of a transverse airflow passage in accordancewith a ninth exemplary embodiment of the present disclosure.

FIG. 17 is an exploded perspective view of a manifold portion and aspacer portion in accordance with a tenth exemplary embodiment of thepresent disclosure.

FIG. 18 is an end view of a transverse airflow passage showing certainfeatures of the present disclosure.

FIG. 19 is a sectional view of the transverse airflow passage of FIG. 17along the lines 18-18.

FIG. 20 is a plan view of a portion of a second conventional internalcombustion engine.

DETAILED DESCRIPTION

Referring to FIG. 1, a portion of an internal combustion engine is shownas a simplified schematic and generally indicated at 10. Engine 10includes an engine body 12, which includes an engine block 14 and aplurality of cylinders (not shown). Engine body 12 also includes aplurality of cylinder heads 16, each of which covers one cylinder andworks with other elements of engine body 12 to form a plurality ofcombustion chambers. Engine 10 also includes an air intake system 18,which includes an intake air circuit 20 and a pair of intake manifolds22 positioned along intake air circuit 20, each intake manifold 22 beingattached to engine body 12. Air intake system 18 may also include aturbocharger 24 positioned along intake air circuit 20. Each intakemanifold 22 includes a plurality of identically configured intakemanifold portions 26 a and 26 b. The combustion chambers, cylinder heads16, and intake manifold portions 26 a are arrayed in a left bank or side28 and the combustion chambers, cylinder heads 16, and intake manifoldportions 26 b a right bank or side 30, which may form a “V”configuration or a straight configuration. Left bank 28 and right bank30 are arranged on opposite sides of a vertically extending engine bodyplane 32. Engine 10 may include other elements and systems (not shown),such as a fuel system, an exhaust system, a control system, and anaftertreatment system.

Engine 10 is of a size class that has relatively low volume production.To minimize cost in engines having relatively low production volume,intake manifold portions 26 a and 26 b are identically configured, andcylinder heads 16 are identically configured. In the context of thisdisclosure, “identically configured” means that each intake manifoldportion 26 a and 26 b has similarly oriented airflow passages, andsimilarly configured mounting locations. Because of the identicalconfiguration, each intake manifold portion 26 a and 26 b isinterchangeable with any other intake manifold portion 26 a or 26 b.Each intake manifold portion 26 a or 26 b is fluidly connected to onecombustion chamber. Each intake manifold portion 26 a or 26 b may bedirectly attached to one cylinder head 16. In the exemplary embodiment,each intake manifold portion 26 a or 26 b is connected to at least oneadjacent intake manifold portion 26 a or 26 b. Regardless of enginesize, it is important for airflow into the combustion chambers toprovide consistent air motion as intake air flows into the combustionchambers to provide similar output power between combustion chambers andto have a uniform flow of emissions from the engine and, if applicable,into the aftertreatment system so that the aftertreatment system is ableto remove or neutralize emissions optimally. The applicant hasdetermined through extensive experimentation and modeling that theconfiguration of intake manifold portions 26 a and 26 b leads to adifference between the amount of swirl in left bank 28 and the amount ofswirl in right bank 30. By modifying the intake manifold portions fromthose of the prior art, the applicant has developed intake manifoldportions that provide significant improvements in swirl uniformity inthe combustion chambers of left bank 28 and right bank 30. By optimizingthe amount of swirl in the combustion chamber, particulate emissions,also called smoke, is minimized, and consistency of power output isimproved cylinder to cylinder and between left bank 28 and right bank30.

Referring to FIG. 3, a portion of left bank 28 and a portion of rightbank 30 are shown. As described hereinabove, and as particularly shownin FIG. 4, each intake manifold portion 26 a and 26 b is identicallyconfigured. Each intake manifold portion 26 a and 26 b includes a bodyportion 34, a plate portion 36, and a connection portion 38 connectingplate portion 36 to body portion 34. Body portion 34 includes bodylongitudinal axis 40, a first end 42, a second end 44 and a longitudinalairflow passage 46 extending along longitudinal axis 40 from first end42 to second end 44. Second end 44 includes an external or outsidediameter 56. Each intake manifold portion 26 a and 26 b further includesa first transverse airflow passage 48 and a second transverse airflowpassage 50 that extend from plate portion 36 through connection portion38 to connect to longitudinal airflow passage 46. First transverseairflow passage 48 and second transverse airflow passage 50 connect tolongitudinal airflow passage 46 at a transverse passage connection angle51 that in the exemplary embodiment is about 90 degrees.

First end 42 includes a flange portion 52 that includes an internal orinside diameter 54 sized to accept outside diameter 56 of second end 44,which permits inserting second end 44 of one intake manifold portion 26a or 26 b within first end 42 of another intake manifold portion 26 a or26 b. When each intake manifold portion 26 a or 26 b is positioned onengine 10, each plate portion 36 is secured to one cylinder head 16 andmay be held in place by a plurality of fasteners 58, clamps, or othermechanisms. Each second end 44 is positioned within first end 42 of anadjacent intake manifold portion 26 a or 26 b, within another element ofintake circuit 20, or covered by a cap 60, as shown in FIG. 1. Eachconnection to second end 44 is sealed using a gasket material, or may besealed using other techniques, such as welding. Similarly, each firstend 42 connects to or mates with second end 44 of an adjacent intakemanifold portion 26 a or 26 b, connects to or mates with another elementof intake circuit 20, or is covered by a cap 62, as shown in FIG. 1.Each connection to first end 42 is sealed using a gasket material, ormay be sealed using other techniques, such as welding. In order to keepengine 10 compact to meet customer expectations, intake manifolds 22 arelocated in a position that requires connection portion 38 to be curvedor curvilinear and to form a transverse passage angle 64, as shown inFIG. 2. The configuration of connection portion 38 thus causes firsttransverse airflow passage 48 and second transverse airflow passage 50to be curved or curvilinear and to include transverse passage angle 64.In an exemplary embodiment, transverse passage angle 64 may be in therange 70 degrees to 135 degrees.

As described hereinabove, each cylinder head 16 is attached to ormounted on engine block 14 and covers a combustion chamber, a portion ofwhich may be seen in FIG. 3 as a hidden line and generally indicated at66. Cylinder head 16 also includes a first head passage 68 and a secondhead passage 70. First head passage 68 connects first transverse airflowpassage 48 to combustion chamber 66. First head passage 68 extendsgenerally along a flat plane until it connects with combustion chamber66 at one side of combustion chamber 66 at a first chamber opening 74.Second head passage 70 connects second transverse airflow passage 50 tocombustion chamber 66. Second head passage 70 extends along a flat plane72, but prior to opening into combustion chamber 66, second head passage70 extends in a clockwise direction from flat plane 72, connecting tocombustion chamber 66 at a second chamber opening 76, when viewingengine 10 from the direction shown in FIGS. 1 and 3.

When engine 10 operates, outside or external air flows from an intakeopening (not shown) into intake air circuit 20. The air may flow throughone or more filters (not shown) and, in the exemplary embodiment,through turbocharger 24. Intake air then flows into intake manifolds 22,one at left bank 28 and one at right bank 30. Though not shown, air mayalso flow through a charge air cooler and through other elementsupstream from intake manifolds 22. Once in intake manifold 22, theintake air flows into each intake manifold portion 26 a or 26 b throughlongitudinal airflow passage 46. In left bank 28, air flows intolongitudinal airflow passage 46 from first end 42 of each intakemanifold portion 26 a. Air then flows into first transverse airflowpassage 48 and second transverse airflow passage 50 of intake manifoldportion 26 a, moving through a first angle, which is transverse passageconnection angle 51. As the airflow passes through first transverseairflow passage 48 and through second transverse airflow passage 50, theairflow flows through a second angle, which is transverse passage angle64. Airflow exiting intake manifold portion 26 a through plate portion36 is shown as a stylized line and indicated at 78 in FIG. 4.

In right bank 30, air flows into longitudinal airflow passage 46 fromsecond end 44 of each intake manifold portion 26 b. Air then flows intofirst transverse airflow passage 48 and second transverse airflowpassage 50 of intake manifold portion 26 b, moving through a firstangle, which is transverse passage connection angle 51. As the airflowpasses through first transverse airflow passage 48 and through secondtransverse airflow passage 50, the airflow flows through a second angle,which is transverse passage angle 64. Airflow exiting intake manifoldportion 26 b through plate portion 36 is shown as a stylized line andindicated at 80 in FIG. 4. Airflow exiting intake manifold portions 26 aand 26 b enters first head passage 68 and second head passage 70 of eachrespective cylinder head 16. The airflow enters combustion chamber 66from first chamber opening 74 of first head passage 68 and from secondchamber opening 76 of second head passage 70. The effect of the positionof first chamber opening 74 and second chamber opening 76 with respectto combustion chamber 66 is to induce a clockwise combustion chamberswirl to intake air flowing into combustion chamber 66 when viewingengine 10 from the direction shown in FIGS. 1 and 3, indicated at 82 inFIG. 3.

Engine 10 works well for its intended purpose, but engine 10 haschallenges. Applicant recognized that one challenge with engine 10 isthat output power and emissions between left bank 28 and right bank 30are different. What was not understood was the reason for thedifferences between left bank 28 and right bank 30. Applicant analyzedand tested each individual component of left bank 28 and right bank 30extensively. What the Applicant unexpectedly learned is that airflow 78exits intake manifold portion 26 a with a clockwise rotation and airflow80 exits intake manifold portion 26 b with a counterclockwise rotation.This rotation is caused by the airflow changing direction a first timethrough transverse passage connection angle 51 and a second time throughtransverse passage angle 64. Because the direction of transverse passageangle 64 is opposed on opposite sides of engine 10, i.e., the left sideand the right side, the direction of airflow rotation that enterscombustion chamber 66 from first head passage 68 and second head passage70 is also opposite on the left side and the right side, i.e., clockwiseversus counterclockwise. Applicant also learned that the direction ofrotation of airflow 78 and airflow 80 affected the amount of swirl incombustion chambers 66.

In one engine configuration, the amount of swirl from airflow into eachleft bank 28 combustion chamber was 20% higher than expected. The amountof swirl from airflow into each right bank 30 combustion chamber 66 was30% lower than expected. Thus, the swirl in right bank 30 was more than40% different from the swirl in left bank 28. Thus, because of therotation induced by longitudinal airflow passage 46, first transverseairflow passage 48, and second transverse airflow passage 50, the swirl,also called flow vortices, in each combustion chamber 66 in left bank 28was actually 20% higher than would be expected if no swirl wasintroduced by travel through the aforementioned passages. Furthermore,the swirl in each combustion chamber 66 in right bank 30 was actually30% lower than would be expected if no swirl was introduced by travelthrough the aforementioned passages. As noted hereinabove, if swirl orflow vortices are too high or too low, smoke emissions increase andpower varies between left bank 28 and right bank 30. Thus, thedifference in swirl between left bank 28 and right bank 30 wasundesirably causing increased particulate emissions and causingundesirable power variations. Flow vortices may also be different fromcylinder to cylinder in the same bank, but these differences aretypically much less than the difference between banks.

To reduce the amount of airflow rotation induced by the configuration ofintake manifold portions 26 a and 26 b, applicant determined that one ormore fin or rib portions placed in first transverse airflow passage 48and in second transverse airflow passage 50 reduced the rotation of airflowing from first transverse airflow passage 48 and second transverseairflow passage 50 to nearly zero. By reducing the airflow rotation tonearly zero, the swirl in the left bank and right bank combustionchambers became nearly equal, which improved the uniformity of mixing ofair and fuel between left bank 28 and right bank 30. The improved mixingimproved the consistency of power output from left bank 28 and rightbank 30 as well as the level of emissions from left bank 28 and rightbank 30, nearly eliminating the previously observed differences.

While internal combustion engine 10 shows a side-by-side configurationfor left bank 28 and right bank 30, the definition of left and rightbank refers as much to the orientation of airflow through an intakemanifold portion as it does to a physical left bank and right bankposition. FIG. 20 shows a conventional internal combustion engine 400including an engine body 402, which further includes a cylinder block406 to which are attached one or more cylinder heads 404. An air intakesystem 408 functions similar to intake system 18 of FIG. 1. Intakesystem 408 includes an intake manifold 410 including a plurality ofintake manifold portions 412 a and 412 b that may be similar to intakemanifold portions 26 a and 26 b. Because air intake system 408 connectsto intake manifold 410 in a central location, intake manifold 410 isdivided into a left bank 414 and a right bank 416, with air flow throughintake manifold portions 412 a as previously described for intakemanifold portions 26 a for left bank 28 and air flow through intakemanifold portions 412 b as previously described for intake manifoldportions 26 b for right bank 30. Thus, an inline internal combustionengine may have a left bank and right bank from the perspective ofairflow.

Referring to FIGS. 5 and 6, a first exemplary embodiment intake manifoldportion 100 of the present disclosure is shown. As with intake manifoldportions 26 a and 26 b, intake manifold portion 100 includes a bodyportion 102, a plate portion 104 having an exterior surface 124, and aconnection portion 106 extending from body portion 102 to plate portion104. Intake manifold portion 100 also includes a body longitudinal axis108, a first end 110, a second end 112, and a body interior surface 113that forms a longitudinal airflow passage 114 extending along bodylongitudinal axis 108. Intake manifold portion 100 also includes a firstinlet opening 134 formed in body interior surface 113 and a first outletopening 120 formed in exterior surface 124 of plate portion 104, and afirst passage interior surface 136 that forms a first transverse airflowpassage 116 positioned or extending between first inlet opening 134 andfirst outlet opening 120. Thus, first inlet opening 134 is at a firstend of first transverse airflow passage 116 and first outlet opening 120is at a second end of first transverse airflow passage 116. Intakemanifold portion 100 further includes a second inlet opening (not shown)formed in body interior surface 113 and a second outlet opening 122formed in exterior surface 124 of plate portion 104, and a secondpassage interior surface 138 that forms a second transverse airflowpassage 118 positioned or extending between the second inlet opening andsecond outlet opening 122. Thus, the second inlet opening is at a firstend of second transverse airflow passage 118 and second outlet opening122 is at a second end of second transverse airflow passage 118. Firsttransverse airflow passage 116 includes a longitudinal first transversepassage axis 130 that extends through the center of first transverseairflow passage 116 between first inlet opening 134 and first outletopening 120. Second transverse airflow passage 118 includes alongitudinal second transverse passage axis 132 that extends through thecenter of first transverse airflow passage 116 between the second inletopening and second outlet opening 122. Each longitudinal transversepassage axis extends at transverse passage connection angle 51 tolongitudinal airflow passage 114, and an extension of each longitudinaltransverse passage axis may intersect body longitudinal axis 108. In anexemplary embodiment, transverse passage connection angle 51 is 90degrees, but may be at other angles. Each transverse airflow passageextends through connection portion 106 to plate portion 104. Firsttransverse passage axis 130 extends from plate portion 104 at transversepassage angle 64 to the portion of transverse passage axis 130 thatextends into longitudinal airflow passage 114 or that may intersect bodylongitudinal axis 108. When intake manifold portion 100 is positioned onengine body 12, first outlet opening 120 and second outlet opening 122are in fluid communication with combustion chamber 66, thus providing aflow path for intake air to reach combustion chamber 66.

Intake manifold portion 100 further includes at least one fin or ribportion 126 formed in at least one of plate portion 104 and connectionportion 106. Each fin or rib portion 126 extends radially inward fromeither first passage interior surface 136 into first transverse airflowpassage 116 and toward first transverse passage axis 130, or from secondpassage interior surface 138 into second transverse airflow passage 118and toward second transverse passage axis 132. Each fin or rib portion126 extends in a direction that is longitudinally along a respectivetransverse airflow passage, i.e., in the same direction that eitherfirst transverse passage axis 130 or second transverse passage axis 132of the respective transverse airflow passage extends. Airflow also flowsthrough first transverse airflow passage 116 along first transversepassage axis 130 toward combustion chamber 66 and through secondtransverse airflow passage 118 along second transverse passage axis 132toward combustion chamber 66. For ease of casting, each fin or ribportion 126 may follow a casting parting line 128 that may be formedduring fabrication of intake manifold portion 100. In the exemplaryembodiment, first transverse airflow passage 116 includes a pair ofoppositely disposed, horizontally extending co-planar fin portions 126,and second transverse airflow passage 118 includes a pair of oppositelydisposed, horizontally extending co-planar fin portions 126. In theexemplary embodiment, each fin portion 126 in the left bank is co-planarwith all other fin portions 126 in the left bank or side, and each finportion 126 is co-planar with all other fin portions 126 in the rightbank or side. However, in the exemplary embodiment, each fin portion 126in one bank is not co-planar with any fins in an opposite bank, thoughthey may be in another embodiment. Because fin portions 126 extendeither along the first transverse passage axis 130 of first transverseairflow passage 116 or along second transverse passage axis 132 ofsecond transverse airflow passage 118, fin portions 126 may have acurvature 140, which may be seen in FIG. 6. Fin portions 126 aredisposed closer to either first outlet opening 120 or second outletopening 122 than to first inlet opening 134 and the second inlet opening(not shown) because the swirl vortices are greater after each transverseairflow passage has extended through curvilinear transverse passageangle 64. In addition, positioning fin portions 126 closer to an outletopening may make forming fin portions 126 during manufacturing easier.In the exemplary embodiment shown in FIG. 6, fin portions 126 extendlongitudinally from either first outlet opening 120 or second outletopening 122.

In the following embodiments, elements having the same number as thefirst exemplary embodiment function similar to the first exemplaryembodiment and any description of previously described elements is forthe purpose of clarity.

Referring to FIG. 7, a second exemplary embodiment intake manifoldportion 150 is shown. As with intake manifold portions 26 a, 26 b, and100, intake manifold portion 150 includes body portion 102, a plateportion 154 having an exterior surface 174, and a connection portion 156extending from body portion 102 to plate portion 154. Intake manifoldportion 150 also includes a first inlet opening (not shown) similar toinlet opening 134 and a first outlet opening 170 formed in exteriorsurface 174 of plate portion 154, and a first passage interior surface180 that forms a first transverse airflow passage 166 positioned orextending between the first inlet opening and first outlet opening 170.Intake manifold portion 150 further includes a second inlet opening (notshown) similar to that described hereinabove and a second outlet opening172 formed in exterior surface 174 of plate portion 154, and a secondpassage interior surface 182 that forms a second transverse airflowpassage 168 positioned or extending between the second inlet opening andsecond outlet opening 172. First transverse airflow passage 166 includesa longitudinal first transverse passage axis 184 that extends betweenthe first inlet opening and first outlet opening 170. Second transverseairflow passage 168 includes a longitudinal second transverse passageaxis 186 that extends between the second inlet opening and second outletopening 172. Each transverse airflow passage extends through connectionportion 156 to plate portion 154.

Intake manifold portion 150 further includes at least one fin or ribportion 176 formed in at least one of plate portion 154 and connectionportion 156. Each fin or rib portion 176 extends radially inward fromeither first passage interior surface 180 into either first transverseairflow passage 166 or from second passage interior surface 182 intosecond transverse airflow passage 168. Each fin or rib 176 may beoriented in a direction perpendicular to the direction of ribs 126 inthe previous embodiment, and thus may be oriented in a generallyvertical direction. In the exemplary embodiment, each fin or rib 176 isparallel to all other fin or rib portions 176 in the left bank or sideand the right bank or side. Each fin or rib portion 176 extends in adirection that is longitudinally along a respective transverse airflowpassage, i.e., in the same direction that either first transversepassage axis 184 or second transverse passage axis 186 of the respectiveairflow passage extends, which is also the direction of airflow throughfirst transverse airflow passage 166 and second transverse airflowpassage 168. In the exemplary embodiment, intake manifold portion 150includes a pair of oppositely disposed fin portions 176. Fin portions176 are disposed closer to either first outlet opening 170 or secondoutlet opening 172 than to the first inlet opening (not shown) and thesecond inlet opening (not shown) because the swirl vortices are greaterafter each transverse airflow passage has extended through previouslydescribed transverse passage angle 64, and thus fin or rib portions 176are most effective in that location. In addition, positioning fin or ribportions 176 closer to an outlet opening may make forming fin or ribportions 176 during manufacturing easier. In the exemplary embodimentshown in FIG. 7, fin or rib portions 176 extend longitudinally fromeither first outlet opening 170 or second outlet opening 172.

Referring to FIGS. 8-10, a cylinder head in accordance with a thirdexemplary embodiment of the present disclosure is shown and generallyindicated at 200. Cylinder head 200 includes an exterior surface 224 anda first head inlet opening 202 and a second head inlet opening 204formed in exterior surface 224. Cylinder head 200 also includes a firsthead interior surface 206 extending inwardly from first head inletopening 202 that forms a first head passage 212. Cylinder head 200further includes a second head interior surface 208 extending inwardlyfrom second head inlet opening 204 that forms a second head passage 214.First head passage 212 extends from first head inlet opening 202 to acombustion chamber, in a manner that is similar to first head passage 68shown in FIG. 3. Second head passage 214 extends from second head inletopening 204 to a combustion chamber, in a manner that is similar tosecond head passage 70 shown in FIG. 3. First head inlet opening 202fluidly connects an airflow passage such as first transverse airflowpassage 48 to first head passage 212. Second head inlet opening 204fluidly connects an airflow passage such as second transverse airflowpassage 50 to second head passage 214. First head passage 212 includes alongitudinal first head passage axis 216 that extends along first headpassage 212, and may be along the centerline of first head passage 212.Second head passage 218 includes a longitudinal second head passage axis218 that extends along second head passage 214, and may be along thecenterline of second head passage 214.

Cylinder head 200 further includes one or more grooves, slots, orchannels 228 formed in first head interior surface 206 and second headinterior surface 208. Each groove or slot 228 extends in a directionthat is along either first head passage axis 216 or second head passageaxis 218. While previously described grooves or slots 228 are describedas extending from various openings in the previous embodiments, eachgroove or slot 228 in the third embodiment extends from a spaceddistance from either first head inlet opening 202 or second head inletopening 204. The reason for the spaced distance is that first headpassage 212 includes a bell mouth portion 220 positioned next to oradjacent to first head inlet opening 202 and second head passage 214includes a bell mouth portion 222 positioned next to or adjacent tosecond head inlet opening 204. Each groove or slot may be cast withincylinder head 200 or may be machined into cylinder head 200.

A fin insert portion 226 is sized and shaped to mate with grooves 228.Fin insert portion 226 includes a longitudinally extending portion 230,and one or more engaging portions 232 that are sized to mate withgrooves 228. Fin insert portion 226 is positioned within at least onegroove 228 by installing fin insert portion 226 into first head inletopening 202 or into second head inlet opening 204. Fin insert portion226 may be a press fit with groove 228, may be welded into groove 228,or may be secured within groove 228 by other means, which means that onegroove 228 may be sufficient to properly position fin insert portion226. If fin insert portion 226 is a loose or slip fit with a pair ofgrooves 228, when an intake manifold portion such as intake manifoldportion 26 a or 26 b is attached, mounted or positioned on cylinder head200, the size and position of intake manifold portion 26 a or 26 bretains fin insert portion 226 within grooves 228. While fin insertportion 226 may mate with grooves 228 for ease of manufacture, fininsert portion 226 may be held in place by a suitable fixture and thenattached to first head interior surface 206 of cylinder head 200 thatforms first head passage 212 or second head interior surface 208 thatforms second head passage 214 by a weld or by other suitable attachmenttechnique.

The configuration of cylinder head 200 provides an opportunity tofurther control airflow entering combustion chamber 66. As shown in FIG.11, a fin insert portion 234 in accordance with a fourth exemplaryembodiment of the present disclosure includes a flat planar portion 242and one or more longitudinal portions 236 extending from flat planarportion 242. Flat planar portion 242 includes one or more engagingportions 244 that provide a function similar to previously describedengaging portions 232. Engaging portions 232 may include deformedportions 246, which may be in the shape of a sine wave or other deformedconfiguration. Each deformed portion 246 engages with grooves slots orchannels 228 and helps to retain fin insert portions 234 within cylinderhead 200.

Each longitudinal portion 236 is deflected, bent, or deformed at aninsert angle 238 with respect to a flat or planar location or position240. In an exemplary embodiment, insert angle 238 is in the range zeroto ten degrees, and each longitudinal portion 236 is deflected in adirection that is opposite to the other longitudinal portion 236 formedon fin insert portion 234. In other embodiments, insert angle 238 may bein the range zero to thirty degrees, depending on the speed of airflowacross fin insert portion 234, the diameter of the associated headpassage, and other factors. The advantage to this configuration is thatit permits using a single cylinder head 200 for left bank 28 and rightbank 30 while enabling modification of airflow through each cylinderhead 200. The configuration of fin insert portion 234 may beadvantageous for increasing or decreasing swirl in combustion chamber 66while maintaining consistency of swirl, similar to the modifications ofairflow described in FIGS. 12-14 hereinbelow.

Fin insert portion 234 works as follows. Intake air flowing from anintake manifold portion flows into first head inlet opening 202 orsecond head inlet opening 204. As the intake air enters first head inletopening 202 or second head inlet opening 204, the intake air containseither clockwise or counterclockwise swirl. As the intake air flows overflat planar portion 242, the intake air swirl is eliminated. As theintake air flows longitudinally along either first head passage 212 orsecond head passage 214, longitudinal portions 236 will induce acontrolled amount of swirl in the intake air. The direction of the swirldepends on the direction of deformation of longitudinal portions 236,which means that the swirl induced by longitudinal portions 236 may beeither clockwise or counterclockwise. The magnitude of insert angle 238determines the magnitude of the induced swirl. As previously noted,insert angle 238 may be in the range plus or minus ten degrees, but maybe in the range plus or minus thirty degrees. One reason for theseranges is that, depending on the dimensions of the associated headpassage, fin insert portion 234 may present a pressure drop to intakeair flow as insert angle 238 increases, reducing the efficiency ofengine 10.

Referring to FIG. 12, a fifth exemplary embodiment of the presentdisclosure is shown. For simplicity in explanation, only arepresentation of a first transverse airflow passage 250 including alongitudinal first transverse passage axis 256 is shown. One or more finor rib portions 252 extend into first transverse airflow passage 250 andlongitudinally along first transverse airflow passage 250 at a fin orrib angle 254 with respect to first transverse passage axis 256 oftransverse airflow passage 250. In an exemplary embodiment, fin or ribangle 254 is in the range zero to ten degrees, but may be in the rangezero to thirty degrees, depending on factors described hereinabove. Thebenefit of the configuration shown is that if a clockwise swirlencounters fin or rib portions 252, the amount of swirl is reduced, butremains clockwise. Fin or rib portions 252 may be inserted from an endof first transverse airflow passage 250, may be cast into airflowpassage 250, or may be attached to an interior wall forming firsttransverse airflow passage 250.

Referring to FIG. 13, a sixth exemplary embodiment of the presentdisclosure is shown. For simplicity in explanation, only arepresentation of a first transverse airflow passage 270 including alongitudinal first transverse passage axis 276 is shown. One or more finor rib portions 272 extend into first transverse airflow passage 270 andlongitudinally along first transverse airflow passage 270 at a fin orrib angle 274 with respect to first transverse passage axis 276 of firsttransverse airflow passage 270. In an exemplary embodiment, fin or ribangle 274 is in the range zero to ten degrees, but may in the range zeroto thirty degrees, as described hereinabove. The benefit of theconfiguration shown is that if a low clockwise swirl encounters ribs272, the amount of swirl is increased, but remains clockwise. Such anincrease may be beneficial when entering combustion chamber 66. The finor rib portions 272 may be inserted from an end of first transverseairflow passage 270, may be cast into first transverse airflow passage270, or may be attached to an interior wall forming first transverseairflow passage 270.

Referring to FIG. 14, a seventh exemplary embodiment of the presentdisclosure is shown. For simplicity in explanation, only arepresentation of a first transverse airflow passage 290 including alongitudinal first transverse passage axis 296 is shown. One or more finor rib portions 292 extend into first transverse airflow passage 290 andlongitudinally along first transverse airflow passage 290 at a fin orrib angle 294 with respect to first transverse passage axis 296 of firsttransverse airflow passage 290. In an exemplary embodiment, fin or ribangle 294 is in the range zero to ten degrees, but may be in the rangezero to thirty degrees. The benefit of the configuration shown is thatif airflow having no swirl encounters fin or rib portions 292, swirl isintroduced into the airflow. Depending on the direction of the angles offin or rib portions 292, the introduction of swirl may be eitherclockwise or counterclockwise. Such an introduction of swirl may bebeneficial when entering combustion chamber 66. Fin or rib portions 292may be inserted from an end of first transverse airflow passage 290, maybe cast into first transverse airflow passage 290, or may be attached toan interior wall forming first transverse airflow passage 290.

While the embodiments of FIGS. 12, 13, and 14 describe fin or rib anglesas being in the range zero up to thirty degrees, more broadly, the finor rib angles of the various fin or rib portions described herein may beadjusted to vary the amount of swirl in combustion chamber 66. A zerodegree fin or rib angle, which corresponds to a fin or rib portionextending along the axis of an airflow passage, yields little or noswirl in the airflow that enters combustion chamber 66. Increasing theangle of a fin or rib portion with respect to the longitudinal axisincreases swirl or reduces swirl, depending on the direction of the finor rib angle. Furthermore, because a fin or rib portion may be angled ineither direction, i.e., either clockwise or counterclockwise whenviewing a fin or rib portion long its length, then the fin or rib angleof a fin or rib portion may be in the range −30 degrees to +30 degrees,depending on the desired effect on airflow. While the angles shown aregenerally flat or fixed angles, the various fin and rib configurationsmay also be formed in a spiral, helical, or corkscrew type shape, aslong as the angle ranges are observed and the dimensions of the fin andrib configuration meet the dimensional requirements describedhereinbelow.

Referring to FIG. 15, an eighth exemplary embodiment of the presentdisclosure is shown. The description of this embodiment is limited tothe first transverse airflow passage for simplicity. An intake manifoldportion 300 includes a first passage interior surface 308 that forms afirst transverse airflow passage 304 including a first transversepassage axis 306 and a fin or rib portion 302 extending from one side offirst transverse airflow passage 304 to an opposite side of firsttransverse airflow passage 304. Fin or rib portion 302 may positionedwithin first transverse airflow passage 304 as described hereinabove,using a forming technique such as casting, inserted into one or moregrooves, or held and attached using a process such as welding. Theprimary advantage to fin or rib portion 302 may be in the ease ofinstalling fin or rib portion 302.

Referring to FIG. 16, a ninth exemplary embodiment of the presentdisclosure is shown. The description of this embodiment is limited tothe first transverse airflow passage for simplicity. An intake manifoldportion 320 includes a first transverse airflow passage 324 and a fin orrib portion 322 that includes a plurality of wall portions 326 thatextend from intake manifold portion 320. Fin or rib portion 322 may bepositioned or formed within first transverse airflow passage 324 aspreviously described. While four wall portions 326 are shown, any numberof wall portions 326 may be included as long as wall portions 326 do notprovide an excessive pressure drop to airflow passing across fin or ribportion 322.

Referring to FIG. 17, a tenth exemplary embodiment of the presentdisclosure is shown. A spacer portion 330 includes a planar surface 342,a first spacer passage 332 that extends longitudinally away from planarsurface 342 into spacer portion 330, and a second spacer passage 334that extends longitudinally away from planar surface 342 into spacerportion 330. Spacer portion 330 is sized and configured to be positionedbetween intake manifold portion 26 a or 26 b and combustion chamber 66.The position of first spacer passage 332 and second spacer passage 334is such that when intake manifold portion 26 a or 26 b is attached tocylinder head 16, intake air is able to flow from first transverseairflow passage 48 into and through first spacer passage 332, then intofirst head passage 68 of cylinder head 16, and then into combustionchamber 66. Intake air is similarly able to flow from second transverseairflow passage 50 into and through second spacer passage 334, then intosecond head passage 70 of cylinder head 16, and then into combustionchamber 66. Spacer portion 330 also includes a plurality of fin or ribportions 336 that are positioned at least partially within first spacerpassage 332 and second spacer passage 334 and may include an interfaceportion 338 the mates with a slot or groove 340 to secure fin or ribportions 336 to prevent movement of fin or rib portions 336. Fin or ribportions 336 extend longitudinally away from planar surface 342 ofspacer portion 330, and may extend perpendicularly to planar surface342. When spacer portion 330 is attached to intake manifold portion 26 aor intake manifold portion 26 b, fin or rib portions 336 extend into andlongitudinally along first transverse airflow passage 48 and secondtransverse airflow passage 50. The advantage of the tenth embodiment isthat it permits the use of all current engine components while achievingthe benefits of the present disclosure described hereinabove.Furthermore, installation of the fin or rib portions is greatlysimplified since they are securely attached to spacer portion 330 priorto insertion into first transverse airflow passage 48 and secondtransverse airflow passage 50. However, spacer portion 330 may only beused in applications that permit moving intake manifolds 22 further fromengine body plane 32.

To provide for optimum effectiveness, the fin or rib portions of thevarious embodiments described herein may be associated with certaindimensional ranges. Referring to FIGS. 18 and 19, a portion of an intakemanifold portion 352 including an interior wall 354 that forms alongitudinal first transverse airflow passage 346, including a firsttransverse passage axis 350 and having a bore diameter B, is shown toillustrate exemplary dimensions suitable for use with the embodimentsdescribed hereinabove. One or more fin or rib portions 348 having athickness T extend from interior wall 354 into airflow passage 346 adistance or width P and along airflow passage 346 a length L. Fin or ribportions 348 illustrate exemplary dimensions suitable for use with theembodiments described hereinabove. Dimensions P, T, L, and B operatebest when meeting the requirements of equations (1), (2), and (3).

$\begin{matrix}{0.10 \leq \frac{P}{B} \leq 0.40} & {{Equation}\mspace{14mu}(1)} \\{0.10 \leq \frac{T}{P} \leq 0.40} & {{Equation}\mspace{14mu}(2)} \\{0.60 \leq \frac{L}{B} \leq 3.00} & {{Equation}\mspace{14mu}(3)}\end{matrix}$In an exemplary embodiment, the ratio of equation (1) is at an optimalvalue at 0.25, the ratio of equation (2) is at an optimal value at 0.25,and the ratio of equation (3) is at an optimal value at 1.0. Aspreviously noted, another aspect of the present disclosure is the needto minimize pressure drop. Thus, the thinnest fin or rib portionpossible is desirable while maintaining the strength and ability to formthe fin or rib portion through the appropriate manufacturing process. Inan exemplary embodiment, the fin or rib portions described hereinaboveare configured in accordance with equation (4).

$\begin{matrix}{0.02 \leq \frac{T}{B} \leq 0.20} & {{Equation}\mspace{14mu}(4)}\end{matrix}$

While various embodiments of the disclosure have been shown anddescribed, it is understood that these embodiments are not limitedthereto. The embodiments may be changed, modified and further applied bythose skilled in the art. Therefore, these embodiments are not limitedto the detail shown and described previously, but also include all suchchanges and modifications.

We claim:
 1. An internal combustion engine, comprising: an engine bodyincluding a plurality of left bank combustion chambers and a pluralityof right bank combustion chambers; a first intake manifold positioned onthe left bank side and a second intake manifold positioned on the rightbank side, each of the first and second intake manifolds attached to theengine body and including a longitudinally extending airflow passage, abody interior surface forming the longitudinally extending airflowpassage, a plurality of inlet openings formed in the body interiorsurface, a plurality of outlet openings, and a plurality of transverseairflow passages, each of the plurality of transverse airflow passagesextending between one of the plurality of inlet openings and one of theplurality of outlet openings and including a longitudinal transversepassage axis, the longitudinal transverse passage axis curved to form atransverse passage angle, the transverse airflow passage positioned tointersect the longitudinally extending airflow passage at a transversepassage connection angle; and a spacer portion positioned between thefirst intake manifold and the engine body and a spacer portionpositioned between the second intake manifold and the engine body, eachspacer portion including a plurality of spacer passages positioned toconnect the plurality of transverse airflow passages to the engine body,and at least one fin portion extending from the spacer portion into eachtransverse airflow passage, the at least one fin being shaped and sizedso as to increase uniformity of combustion between cylinders.
 2. Theinternal combustion engine of claim 1, each intake manifold including afirst transverse airflow passage and a second transverse airflowpassage, the spacer portion including a first spacer passage positionedto connect the first transverse airflow passage to the engine body andthe spacer portion including a second spacer passage positioned toconnect the second transverse airflow passage to the engine body, a pairof fin portions extending from the spacer portion into the firsttransverse airflow passage and a pair of fin portions extending from thespacer portion into the second transverse airflow passage.
 3. Theinternal combustion engine of claim 1, wherein each transverse airflowpassage has a diameter of B and the at least one fin portion has a widthP, and the ratio P/B is in the range 0.10 to 0.40.
 4. The internalcombustion engine of claim 1, wherein each transverse airflow passagehas a diameter of B and the at least one fin portion has a thickness ofT, and the ratio T/B is in the range 0.02 to 0.20.
 5. The internalcombustion engine of claim 1, wherein each transverse airflow passagehas a diameter of B and the at least one fin portion has a length L, andthe ratio L/B is in the range 0.60 to 3.00.
 6. The internal combustionengine of claim 1, wherein the at least one fin portion has a thicknessT and a width P, and the ratio T/P is in the range 0.10 to 0.40.
 7. Theinternal combustion engine of claim 1, the engine body further includinga plurality of cylinder heads, and each spacer portion is attached to acylinder head.
 8. The internal combustion engine of claim 1, wherein theat least one fin portion extends from the spacer portion into eachtransverse airflow passage in a direction along the longitudinaltransverse passage axis.
 9. The internal combustion engine of claim 1,the at least one fin being shaped and sized so as to increase uniformityof combustion between the left and right cylinder banks.
 10. Theinternal combustion engine of claim 1, the at least one fin being shapedand sized so as to increase uniformity of charge flow provided to thecylinders.